Robert Irwin and Witney Carson quickly sparked romance rumours among fans when the celebrity conservationist made his Dancing With The Stars US debut last week.

Viewers at home remarked on their sizzling chemistry during their first dance together, and again this week during their ‘hot’ tango.

But followers of the Aussie star, 21, who is ten years younger than Witney, 31, may be disappointed to discover the choreographer is already married.

The US dancer and the Aussie star have not struck up a romance, given Witney happily tied the knot with her high school sweetheart, Carson McAllister, in 2016.

The pair also share two children together, sons Kevin Leo and Jet Carson.

Nevertheless, it appears Robert and Witney have a close working relationship, with the I’m A Celebrity host hailing her ‘the best dance partner’.

Robert Irwin, 21, and Witney Carson, 31, quickly sparked romance rumours among fans when the celebrity conservationist made his Dancing With The Stars US debut last week. Both pictured

The pair set tongues wagging again this week after Robert had viewers blushing during his latest dance with the blonde beauty.

The Aussie conservationist took to the dance floor on Tuesday night alongside his partner Witney to perform a tango – and it was sizzling.

This week’s theme, One Hit Wonders, saw the couple dance to the 2002 hit Move Your Feet, with Robert receiving a standing ovation from the live studio audience.

But it was his raunchy performance that really had people riled up.

The routine began with Robert staring intensely into Witney’s eyes before launching into a sultry tango.

Prowling across the stage with his blonde bombshell of a partner, Robert’s sensual air was a world away from his usual demeanour as Australia’s national treasure.

What’s more, midway through their routine, Robert and Witney broke out into retro noughties dance moves as a tribute to the iconic song’s origins.

Ditching the tango, they had the crowd – including Robert’s mum Terri and sister Bindi – in stitches while doing the robot, before breaking it down on the floor, hip-hop style.

Viewers at home remarked on their sizzling chemistry during their first dance together, and again this week during their ‘hot’ tango

However, Witney happily tied the knot with her high school sweetheart, Carson McAllister, in 2016. The pair also share two children together, sons Kevin Leo and Jet Carson. All pictured

The saucy tango saw Robert receive an 8 from Carrie Ann, and a 7 from both Derek and Bruno, for a total of 22 out of 30, keeping him at the top of the leaderboard.

Fans flooded the DWTS Instagram page gushing over Robert’s blush-worthy performance.

‘Such a sexy tango,’ one person wrote.

Another chimed in: ‘Love this hot tango tonight so much, it’s so amazing.’

However, other fans predicted Robert’s talent on the dance floor could see him take home the Mirrorball Trophy.

‘He is going to win this!’ one person wrote.

Another added: ‘So we all agree this is our mirror ball champ right?’

‘Everybody else sorry, but you need to pack up and go home,’ one more fan penned.